User-configurable settings for content obfuscation

ABSTRACT

An aspect of providing user-configurable settings for content obfuscation includes, for each media segment in a media file, inputting the media segment to a neural network, applying a classifier to features output by the neural network, and determining from results of the classifier images in the media segment that contain the sensitive characteristics. The classifier specifies images that are predetermined to include sensitive characteristics. An aspect further includes assigning a tag to each of the images in the media segment that contain the sensitive characteristics. The tag indicates a type of sensitivity. An aspect also includes receiving at least one user-defined sensitivity, the user-defined sensitivity indicating an action or condition that is considered objectionable to a user, identifying a subset of the tagged images that correlate to the user-defined sensitivity, and visually modifying, during playback of the media file, an appearance of the subset of the tagged images.

BACKGROUND

The invention relates generally to information processing, and morespecifically, to user-configurable settings for content obfuscation.

Different types of audiences may have varying degrees of sensitivitieswhen it comes to experiencing certain video content. For example, imagesdepicting violence or cruelty may not be suitable for young children whohave not yet developed self-soothing skills necessary to cope with thedistress induced by witnessing the violence. In addition, violent imagescan have a harmful effect on those individuals who may suffer from posttraumatic stress disorder (PTSD) or other sensitivities.

SUMMARY

According to an embodiment a method, system, and computer programproduct for providing user-configurable settings for content obfuscationis provided. A method includes for each media segment in a media file,inputting, via a computer processor, the media segment to a neuralnetwork, applying a classifier to features output by the neural network,and determining from results of the classifier images in the mediasegment that contain the sensitive characteristics. The classifierspecifies images that are predetermined to include sensitivecharacteristics. The method also includes assigning, via the computerprocessor, a tag to each of the images in the media segment that containthe sensitive characteristics, receiving at least one user-definedsensitivity, and identifying a subset of the tagged images thatcorrelate to the user-defined sensitivity. The user-defined sensitivityindicates an action or condition that is considered objectionable to auser. The method further includes visually modifying, during playback ofthe media file, an appearance of the subset of the tagged images.

Additional features and advantages are realized through the techniquesof the invention. Other embodiments and aspects of the invention aredescribed in detail herein and are considered a part of the claimedinvention. For a better understanding of the invention with theadvantages and the features, refer to the description and to thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The forgoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings, which:

FIG. 1 depicts a block diagram of a component architecture upon whichuser-configurable settings for content obfuscation may be implemented inaccordance with an embodiment of the invention;

FIG. 2 depicts a block diagram of a system upon which user-configurablesettings for content obfuscation may be implemented in accordance withan embodiment of the invention;

FIG. 3 depicts a flow diagram of a process for implementinguser-configurable settings for content obfuscation according to anembodiment of the invention; and

FIG. 4 depicts a user interface screen including sample user-specifiedsensitivities and feedback in accordance with an embodiment of theinvention.

DETAILED DESCRIPTION

Exemplary embodiments provide user-configurable settings for contentobfuscation. The user-configurable settings for content obfuscationprovide modification of video elements based on user-definedsensitivities. The sensitivities may include, e.g., emotional response,privacy, security, or other sensitivities. Elements subject toobfuscation may include images depicting objects used in the commissionof violent acts, faces of people subject to privacy concerns, victims ofviolence, or any element that is determined to contribute to the definedsensitivities. In an embodiment, the user-configurable settings forcontent obfuscation estimates the potential harm caused to a particularuser if the system did not obfuscate the content. This allows for activelearning used to optimize, through time, the nature of the obfuscation.The user-configurable settings for content obfuscation are configured touse prediction, machine learning algorithms, and neural networks, suchas a deep convolutional neural network.

Turning now to FIG. 1, a component architecture 100 for implementinguser-configurable settings for content obfuscation will now be describedin accordance with an embodiment.

The architecture 100 includes media content 102, a content analyzer 104,and training data 106. The content 102 may be multimedia content, suchas consumer programming. Alternatively, the content 102 may be asurveillance or security video. The training data 106 may be createdfrom a corpus of input videos. Using learning techniques, high-levelfeatures (e.g., blood, weapon, lying body, etc.) are identified from theinputs. A classifier, such as a support vector machine, can be appliedto the features to predict sensitive content or elements, as well as aconfidence value that indicates a degree to which the features representsensitive subject matter.

In an embodiment, the content 102 is analyzed against the training data106 via the content analyzer 104, and the content analyzer 104 generatesa content index including sensitive characteristics and a correspondingconfidence score. The content analyzer 104 may include machine learningtechniques, such as a neural network to process the content. The contentis also referred to herein as a media file. In an embodiment, the mediafile may be broken down into media segments or video frames andprocessed by the neural network to produce high-level features that areextracted, e.g., from the last layer of the neural network. A featurevector is formed from the set of features, which is fed to a classifier.Based on the classifier, a sensitivity indication is determined for themedia segment. The media segment is tagged to indicate its sensitivity.In an embodiment, the tag may specify a type of sensitivity based on theresults of the classifier. For example, if the media segment contains ahuman face, the tag may indicate a type ‘private,’ while a media segmentcontaining a disfigured or otherwise injured human face may be taggedwith a tag type ‘emotional response.’ In the first example, the tag‘private’ may be used for sensitivities in which a person's identity isto be protected, while in the second example, the tag ‘emotionalresponse’ may be used for sensitivities in which a person is emotionallyimpacted by certain images (e.g., young children, individuals with PTSD,etc.).

The confidence score indicates a value representing the level ofconfidence that a selected image from the content 102 matches an imagefrom the training data 106. The confidence score may be calculated byanalysis of the content. In an embodiment, the content may be processedusing natural language processing (NLP) techniques, voice stressanalysis, and/or contextual information. Voice stress analysis may beanalyzed through one or more techniques implemented by the contentanalyzer 104 that detects and evaluates amplitude and frequency of audiocomponents. In one embodiment, e.g., if the NLP analysis determines thatthe word “blood” has been uttered, and within a proximate threshold timeperiod the voice stress analysis reflects that a scream has beenuttered, the process may infer a high confidence that the subject mattercontains sensitive subject matter. In addition, the confidence score maybe determined for different cohorts of viewers of the content. Forexample, if the viewer is likely to be someone with greater than averagesensitivities (e.g., autism, pre-Alzheimer's, or PTSD), then theconfidence score for sensitive subjects may be increased, as theseindividuals may be more likely to find certain content objectionable. Inone example, if a classifier suggests that blood is shown in thecontent, and the word blood is uttered in a stressed voice, and theviewer suffers from PTSD (e.g., as determined by a user profile that isaccessible to the content analyzer 104, analysis of the viewer's facialexpressions (e.g., conveyed from a facial features analysis component ata user device to the content analyzer 104, etc.), then the confidencethat the matter is sensitive is increased. In addition, viewer votingmay be used to change the confidence levels. For example, if a moviescene of blood is voted by viewers to be stressful (including the use ofvoting done via biometric analysis of one or more viewers), then thenext time this movie or other movie is played, the confidence of thesensitivity is increased for this classifier.

The architecture 100 also includes an obfuscator engine 108, usersettings 110, and an obfuscated content player 112. The user settings110 enable the selection of options by a user to indicate what types ofelements in a media file are considered to be sensitive to that user orfamily of users. A sample user interface illustrating the user settingsis shown in FIG. 4. In an embodiment, the obfuscator engine 108 receivesthe content 102, and the user settings 110 are applied, in conjunctionwith the index, via the obfuscator engine 108. The obfuscator engine 108outputs obfuscated content, which is provided for playback on theobfuscated content player 112. The media file may be obfuscated using avariety of techniques. For example, a predefined image may besuperimposed over the objectionable image. Alternatively, a blurringtechnique may be used in which the spatial resolution of portions of theimage is reduced. In an embodiment, the type of obfuscation may be aselectable parameter provided to the user.

The architecture 100 also includes a feedback loop in which informationderived from the obfuscated video playback is provided to a feedbackanalyzer 114, and the feedback analyzer 114 processes the informationand incorporates the information into the training data 106.

Turning now to FIG. 2, a system 200 upon which the user-configurablesettings for content obfuscation may be implemented will now bedescribed in one embodiment. The system 200 includes end user devices202A and 202B and a content server computer 208, each of which iscommunicatively coupled to one or more networks 206. The end userdevices 202A and 202B are collectively referred to as user devices 202.Each of the end user devices 202 corresponds to the obfuscated contentplayer 112 of FIG. 1.

The user device 202A may be general-purpose computer, e.g., a desktop,laptop, etc. The user device 202B may be a portable communicationsdevice, such as a smart phone, tablet, personal digital assistant, etc.In an embodiment, each of the user devices implements a contentobfuscation application 204. The user devices 202 may represent consumerdevices owned and/or operated by one or more individuals. The userdevices 202 may each also store user settings established through thecontent obfuscation application 204, as well as obfuscated content. Auser who plays media files at the user devices is referred to herein asa viewer.

The content server computer 208 is a network resource that is accessibleby the user devices 202 over one or more networks, such as network(s)206. In an embodiment, the content server computer 208 may beimplemented by a content provider enterprise that distributes content(e.g., broadcast, cable, premium programming, etc.) to end users.Alternatively, the content server computer 208 may be implemented by athird-party application service provider that hosts or manages contentdistribution and related services for one or more content providerenterprises. In a further embodiment, the content server computer 208may be implemented by a video monitoring service that monitorssurveillance video from various entities, such as businesses orhouseholds.

A storage device 210 is communicatively coupled to the content servercomputer 208. The storage device 210 stores content (content 102) fordistribution, as well as training data (training data 106). In oneembodiment, the content may be consumer programming. In addition, thecontent may include surveillance or security video.

The training data is updated over time based on feedback associated withobfuscated video that has been presented to end users. The training datamay also be updated from further processing of media files via neuralnetworks that can further refine the feature vectors, which can resultin greater confidence scores of resulting tagged images.

Networks 206 may include a combination of one or more different types ofnetworks (e.g., local area network, wide area network, Internet,satellite, or terrestrial network, to name a few).

While only one content server computer 208 is shown in FIG. 2, for easeof description, it will be understood that multiple content servercomputers may be implemented in order to realize the advantages of theembodiments herein. For example, one content server computer maydistribute content over a broadband cable network, while another contentserver computer may distribute content as on-demand Internet streamingmedia for subscribing users.

Turning now to FIG. 3, a process for implementing the user-configurablesettings for content obfuscation will now be described in an embodiment.The process in blocks 302-308 are iteratively performed for each mediasegment of a given media file.

At block 302, a media segment is input to a neural network. In anon-limiting embodiment, the neural network may be a deep convolutionalneural network. The output of the neural network includes featuresassociated with the media segment. At block 304, a classifier (e.g.,training data) is applied to features output by the neural network. Theclassifier specifies images that are predetermined to include sensitivecharacteristics.

In block 306, images from the media segment determined to contain thesensitive characteristics are ascertained based on the classifier. Forexample, in an action movie, sensitive characteristics may includeweapons, acts of violence, blood, or other similar characteristics. Inblock 308, a tag is assigned to each of the images in the media segmentthat contain the sensitive characteristics. The tag indicates a type ofsensitivity (e.g., private, security, emotional response) and may alsoinclude a descriptive indicator of the nature of the sensitivecharacteristic. An index may be generated that includes the taggedelements.

In block 310, a user who is interested in viewing the media file entersone or more user-defined sensitivities into a user interface provided bythe content obfuscation application. A sample user interface 400 isshown in FIG. 4. In one embodiment, the user may preselect thesensitivities that are to be applied globally to any media filereceived. In another embodiment, the user may enter sensitivities on amedia file-by-media file basis. In a further embodiment, a compiledlisting of sensitivities (e.g., via the index) for a given media filemay be presented to the user, such that the user can select from thelisting which sensitivities to apply when obfuscating aspects of themedia file. The sensitivities can be broadly defined (e.g., acts ofviolence) or may be more granular in nature (e.g., blood, a war scene,etc.). A user-defined sensitivity may indicate any action or conditionthat is considered objectionable to the user and which can be identifiedfrom a media file through the processing described herein.

As shown in FIG. 4, a user may select a type of sensitivity throughoption 402. The user may then enter any particular sensitivities throughoption 404 or may select from a preset listing through option 406. Theuser may also select an obfuscation technique to apply using option 408.For example, the user can select reduced resolution or substitute image.The substitute image can be one of various images that are presented forthe user to select from. As indicated above, the user-configurablesettings for content obfuscation collects feedback from the user, whichcan be implemented through option 410.

In an embodiment, the content obfuscation application identifies asubset of the tagged images that correlate to the user-definedsensitivities, and in block 312, the content obfuscation applicationvisually modifies, during playback of the media, an appearance of thesubset of the tagged images. The content obfuscation application mayobfuscate a single aspect or portion of an image (e.g., a weapon) whileleaving the remaining features of the image intact so as to maintaincontext for the viewer. For example, suppose the media file is adocumentary about World War II and a parent is interested in obscuringimages in a least restrictive manner so that the educational content ofthe media file can be experienced.

As indicated above, the feedback option (option 410) enables the user torate the obfuscation technique selected, as well as provide additionaluseful information. The process includes evaluating the rating againstratings from other users having matching sensitivities of the user. Theprocess can use the results of the evaluation to suggest a particularobfuscation technique to future users having the matching sensitivities.

In an embodiment, the user-configurable settings for content obfuscationmay be configured to obfuscate audio portions of media files that aredetermined to impact a user's sensitivities. For example, using soundwave analysis, a media segment in which a sound wave frequency exceedssome predetermined threshold may be obfuscated by reducing the volume ofthe audio or masking the audio with another sound file. In anembodiment, the identified portion of the audio may be tagged with atype of sensitivity similar to the tagging applied to video portions.The audio obfuscation techniques can be applied in synchrony with videoobfuscation techniques, such that e.g., if a loud scream is accompaniedby an act of violence, the sound and image portions of the file can beobfuscated.

Technical effects and benefits include providing user-configurablesettings for content obfuscation. The user-configurable settings forcontent obfuscation provide modification of video elements based onuser-defined sensitivities. The sensitivities may include, e.g.,emotional response, privacy, security, or other sensitivities. Elementssubject to obfuscation may include images depicting objects used in thecommission of violent acts, faces of people subject to privacy concerns,victims of violence, or any element that is determined to contribute tothe defined sensitivities. The user-configurable settings for contentobfuscation are configured to use prediction, machine learningalgorithms, and neural networks, such as a deep convolutional neuralnetwork.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A method, comprising: for each media segment in amedia file: inputting, via a computer processor, the media segment to aneural network; applying a classifier to features output by the neuralnetwork, the classifier specifying images that are predetermined toinclude sensitive characteristics; determining, from results of theclassifier, images in the media segment that contain the sensitivecharacteristics; and assigning, via the computer processor, a tag toeach of the images in the media segment that contain the sensitivecharacteristics, the tag indicating a type of sensitivity; receiving atleast one user-defined sensitivity, the user-defined sensitivityindicating an action or condition that is considered objectionable to auser; identifying a subset of the tagged images that correlate to theuser-defined sensitivity; and visually modifying, during playback of themedia file, an appearance of the subset of the tagged images; the methodfurther comprising receiving a user-selected obfuscation technique,wherein visually modifying an appearance of the subset of the taggedimages includes applying the user-selected obfuscation technique to thesubset of the tagged images; receiving feedback from the user responsiveto the playback of the media file, the feedback comprising a ratingspecifying a degree to which the obfuscation technique alleviated asensitivity of the user while maintaining context of the media file;evaluating the rating against ratings from other users having matchingsensitivities of the user; and using results of the evaluating tosuggest a particular obfuscation technique to future users having thematching sensitivities.
 2. The method of claim 1, wherein the visuallymodifying an appearance of the subset of the tagged images includes atleast one of: superimposing a substitute image over a portion of acorresponding tagged image; and reducing resolution of a portion of acorresponding tagged image.
 3. The method of claim 1, wherein the typeof sensitivity includes at least one of: privacy; security; andemotional response.
 4. The method of claim 1, wherein the media file isa surveillance video, the type of sensitivity is privacy, and thevisually modifying an appearance of the subset of the tagged imagesincludes obfuscating a human face detected in the media file.
 5. Themethod of claim 1, further comprising: calculating a confidence valuefor each of the tagged images, the confidence value indicating a levelof confidence that the corresponding tagged image resulting from theclassifier reflects sensitive subject matter, wherein the confidencevalue is determined as a function of contextually related features inthe media file, at least one of which includes the sensitivecharacteristics.
 6. A system, comprising: a memory having computerreadable instructions; and a processor for executing the computerreadable instructions, the computer readable instructions including: foreach media segment in a media file: inputting the media segment to aneural network; applying a classifier to features output by the neuralnetwork, the classifier specifying images that are predetermined toinclude sensitive characteristics; determining, from results of theclassifier, images in the media segment that contain the sensitivecharacteristics; and assigning a tag to each of the images in the mediasegment that contain the sensitive characteristics, the tag indicating atype of sensitivity; receiving at least one user-defined sensitivity,the user-defined sensitivity indicating an action or condition that isconsidered objectionable to a user; identifying a subset of the taggedimages that correlate to the user-defined sensitivity; and visuallymodifying, during playback of the media file, an appearance of thesubset of the tagged images; the computer readable instructions furthercomprising receiving a user-selected obfuscation technique, whereinvisually modifying an appearance of the subset of the tagged imagesincludes applying the user-selected obfuscation technique to the subsetof the tagged images; receiving feedback from the user responsive to theplayback of the media file, the feedback comprising a rating specifyinga degree to which the obfuscation technique alleviated a sensitivity ofthe user while maintaining context of the media file; evaluating therating against ratings from other users having matching sensitivities ofthe user; and using results of the evaluating to suggest a particularobfuscation technique to future users having the matching sensitivities.7. The system of claim 6, wherein the visually modifying an appearanceof the subset of the tagged images includes at least one of:superimposing a substitute image over a portion of a correspondingtagged image; and reducing resolution of a portion of a correspondingtagged image.
 8. The system of claim 6, wherein the type of sensitivityincludes at least one of: privacy; security; and emotional response. 9.The system of claim 6, wherein the media file is a surveillance video,the type of sensitivity is privacy, and the visually modifying anappearance of the subset of the tagged images includes obfuscating ahuman face detected in the media file.
 10. The system of claim 6,wherein the computer readable instructions further comprise: calculatinga confidence value for each of the tagged images, the confidence valueindicating a level of confidence that the corresponding tagged imageresulting from the classifier reflects sensitive subject matter, whereinthe confidence value is determined as a function of contextually relatedfeatures in the media file, at least one of which includes the sensitivecharacteristics.
 11. A computer program product comprising a computerreadable storage medium having program instructions embodied therewith,wherein the computer readable storage medium is not a transitory signalper se, the program instructions executable by a computer processor tocause the computer processor to perform a method comprising: for eachmedia segment in a media file: inputting the media segment to a neuralnetwork; applying a classifier to features output by the neural network,the classifier specifying images that are predetermined to includesensitive characteristics; determining, from results of the classifier,images in the media segment that contain the sensitive characteristics;and assigning a tag to each of the images in the media segment thatcontain the sensitive characteristics, the tag indicating a type ofsensitivity; receiving at least one user-defined sensitivity, theuser-defined sensitivity indicating an action or condition that isconsidered objectionable to a user; identifying a subset of the taggedimages that correlate to the user-defined sensitivity; and visuallymodifying, during playback of the media file, an appearance of thesubset of the tagged images; the program instructions are furtherexecutable to perform: receiving a user-selected obfuscation technique,wherein visually modifying an appearance of the subset of the taggedimages includes applying the user-selected obfuscation technique to thesubset of the tagged images; receiving feedback from the user responsiveto the playback of the media file, the feedback comprising a ratingspecifying a degree to which the obfuscation technique alleviated asensitivity of the user while maintaining context of the media file;evaluating the rating against ratings from other users having matchingsensitivities of the user; and using results of the evaluating tosuggest a particular obfuscation technique to future users having thematching sensitivities.
 12. The computer program product of claim 11,wherein the visually modifying an appearance of the subset of the taggedimages includes at least one of: superimposing a substitute image over aportion of a corresponding tagged image; and reducing resolution of aportion of corresponding tagged image.
 13. The computer program productof claim 11, wherein the type of sensitivity includes at least one of:privacy; security; and emotional response.
 14. The computer programproduct of claim 11, wherein the media file is a surveillance video, thetype of sensitivity is privacy, and the visually modifying an appearanceof the subset of the tagged images includes obfuscating a human facedetected in the media file.
 15. The computer program product of claim11, wherein the program instructions are further executable to perform:calculating a confidence value for each of the tagged images, theconfidence value indicating a level of confidence that the correspondingtagged image resulting from the classifier reflects sensitive subjectmatter, wherein the confidence value is determined as a function ofcontextually related features in the media file, at least one of whichincludes the sensitive characteristics.